Bacterial contamination of dental water lines is a major concern in modern dentistry and may cause infection in dental patients with compromised immune systems. This includes patients with cancer, diabetes, or AIDS;cardiac patients who often require prophylactic antibiotics prior to dental treatment;the elderly, young children, and pregnant women. Bacterial levels in dental water lines can reach 5,000 times the American Dental Association's recommended upper limit for safety. Both the American Dental Association and the Centers for Disease Control advocate regular infection control procedures to disinfect the waterlines. Current disinfection methods (prolonged flushing, daily draining, filters, chemical disinfectants) require regular maintenance and application, which may be impracticable in a busy dental practice. Bacteria often reside in a biofilm, a dense slimy extracellular matrix in which the majority of bacteria are in a dormant metabolic state. These dormant bacteria are often unaffected by conventional antibiotics. Regular dental line disinfectants rarely remove this biofilm. A more compelling solution would be to prevent biofilm formation in the first place. In this Phase II STTR project, we will follow up on the results from our Phase I project to produce a commercially viable dental water line that resists bacterial biofilm formation. In Phase I we showed the following: 1. We developed several methods for covalently attaching organo-selenium to polyurethane (the main polymer used to make dental waterlines). 2. We showed that organo-selenium could be uniformly coated on the lumen of polyurethane tubing following prior treatment with ethylene oxide. 3. We showed that selenium attached to the lumen of polyurethane tubing inhibited biofilm formation. 4. We showed that the selenium attached to the polyurethane was stable after 90 days of soaking in phosphate buffered saline. In Phase II of this project we will: 1) optimize the ethylene oxide technique that we have developed for the attachment of selenium on the inside of dental waterline tubing;2) develop a coating process that can be used commercially;and 3) test the tubing in a dental practice setting for its potential for commercialization. PUBLIC HEALTH RELEVANCE: The American Dental Association and Centers for Disease Control have identified bacterial contamination of dental water lines as a public health concern, particularly for patients with compromised immune systems, and advocate regular use of infection control procedures to address this issue. Conventional disinfecting treatments require regular attention and maintenance by dental staff. We have shown in phase I that we can attach selenium to the lumen of the polyurethane tubing used in dental waterlines and permanently block bacterial attachment. In this phase II project we will do the following: 1) optimize the ethylene oxide technique that we have developed for the attachment of selenium on the inside of dental waterline tubing, 2) develop a selenium coating process that can be used commercially, and 3) test the coated tubing in a dental practice setting for its potential for commercialization.